/* this file is part of xreader, a generic document viewer
 *
 *  Copyright (C) 2004 Red Hat, Inc.
 *  Copyright (C) 2004, 2005 Anders Carlsson <andersca@gnome.org>
 *
 *  Authors:
 *    Jonathan Blandford <jrb@alum.mit.edu>
 *    Anders Carlsson <andersca@gnome.org>
 *
 * Xreader is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * Xreader is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <string.h>
#include <math.h>

#include <glib/gi18n.h>
#include <gtk/gtk.h>

#include "ev-document-misc.h"
#include "ev-document-thumbnails.h"
#include "ev-job-scheduler.h"
#include "ev-sidebar-page.h"
#include "ev-sidebar-thumbnails.h"
#include "ev-utils.h"
#include "ev-window.h"

#define THUMBNAIL_MIN_WIDTH     50
#define THUMBNAIL_MAX_WIDTH     500
#define THUMBNAIL_STEP_WIDTH    20
#define THUMBNAIL_DEFAULT_WIDTH 100

/* The IconView doesn't scale nearly as well as the TreeView, so we arbitrarily
 * limit its use */
#define MAX_ICON_VIEW_PAGE_COUNT 1500

typedef struct _EvThumbsSize
{
	gint width;
	gint height;
} EvThumbsSize;

typedef struct _EvThumbsSizeCache {
	gboolean uniform;
	gint uniform_width;
	gint uniform_height;
	EvThumbsSize *sizes;
} EvThumbsSizeCache;

struct _EvSidebarThumbnailsPrivate {
	GtkWidget *swindow;
	GtkWidget *icon_view;
	GtkWidget *tree_view;
	GtkAdjustment *vadjustment;
	GtkListStore *list_store;
	GHashTable *loading_icons;
	EvDocument *document;
	EvDocumentModel *model;
	EvThumbsSizeCache *size_cache;
	gint n_pages, pages_done;

	int rotation;
	gboolean inverted_colors;

	int thumbnail_width;

	/* Visible pages */
	gint start_page, end_page;
};

enum {
	COLUMN_PAGE_STRING,
	COLUMN_PIXBUF,
	COLUMN_THUMBNAIL_SET,
	COLUMN_JOB,
	NUM_COLUMNS
};

enum {
	SIZE_CHANGED,
	NUM_SIGNALS
};

enum {
	PROP_0,
	PROP_WIDGET,
};

static guint signals[NUM_SIGNALS] = { 0 };

static void         ev_sidebar_thumbnails_clear_model      (EvSidebarThumbnails     *sidebar);
static gboolean     ev_sidebar_thumbnails_support_document (EvSidebarPage           *sidebar_page,
							    EvDocument              *document);
static void         ev_sidebar_thumbnails_page_iface_init  (EvSidebarPageInterface  *iface);
static const gchar* ev_sidebar_thumbnails_get_label        (EvSidebarPage           *sidebar_page);
static void         thumbnail_job_completed_callback       (EvJobThumbnail          *job,
							    EvSidebarThumbnails     *sidebar_thumbnails);
static void         adjustment_changed_cb                  (EvSidebarThumbnails     *sidebar_thumbnails);
static void         ev_sidebar_thumbnails_reload           (EvSidebarThumbnails     *sidebar_thumbnails);
static gboolean     refresh                                (EvSidebarThumbnails     *sidebar_thumbnails);

G_DEFINE_TYPE_EXTENDED (EvSidebarThumbnails,
                        ev_sidebar_thumbnails,
                        GTK_TYPE_BOX,
                        0,
                        G_ADD_PRIVATE (EvSidebarThumbnails)
                        G_IMPLEMENT_INTERFACE (EV_TYPE_SIDEBAR_PAGE,
					       ev_sidebar_thumbnails_page_iface_init))

/* Thumbnails dimensions cache */
#define EV_THUMBNAILS_SIZE_CACHE_KEY "ev-thumbnails-size-cache"

static EvThumbsSizeCache *
ev_thumbnails_size_cache_new (EvDocument *document, gint width)
{
	EvThumbsSizeCache *cache;
	EvRenderContext *rc = NULL;
	gint i, n_pages;
	EvThumbsSize *thumb_size;

	cache = g_new0 (EvThumbsSizeCache, 1);

	n_pages = ev_document_get_n_pages (document);

	/* Assume all pages are the same size until proven otherwise */
	cache->uniform = TRUE;

	for (i = 0; i < n_pages; i++) {
		EvPage *page;
		gdouble page_width, page_height;
		gint    thumb_width = 0;
		gint    thumb_height = 0;

		page = ev_document_get_page (document, i);

		if (document->iswebdocument == FALSE ) {
			ev_document_get_page_size (document, i, &page_width, &page_height);
		}
		else {
			/* Hardcoding these values to a large enough dimesnsion so as to achieve max content without loss in visibility*/
			page_width = 800;
			page_height = 1080;
		}
		if (!rc) {
			rc = ev_render_context_new (page, 0, (gdouble)width / page_width);
		} else {
			ev_render_context_set_page (rc, page);
			ev_render_context_set_scale (rc, (gdouble)width / page_width);
		}

		ev_document_thumbnails_get_dimensions (EV_DOCUMENT_THUMBNAILS (document),
						       rc, &thumb_width, &thumb_height);

		if (i == 0) {
			cache->uniform_width = thumb_width;
			cache->uniform_height = thumb_height;
		} else if (cache->uniform &&
			   (cache->uniform_width != thumb_width ||
			    cache->uniform_height != thumb_height)) {
			/* It's a different thumbnail size.  Backfill the array. */
			int j;

			cache->sizes = g_new0 (EvThumbsSize, n_pages);

			for (j = 0; j < i; j++) {
				thumb_size = &(cache->sizes[j]);
				thumb_size->width = cache->uniform_width;
				thumb_size->height = cache->uniform_height;
			}
			cache->uniform = FALSE;
		}

		if (! cache->uniform) {
			thumb_size = &(cache->sizes[i]);

			thumb_size->width = thumb_width;
			thumb_size->height = thumb_height;
		}

		g_object_unref (page);
	}

	if (rc) {
		g_object_unref (rc);
	}

	return cache;
}

static void
ev_thumbnails_size_cache_get_size (EvThumbsSizeCache *cache,
				   gint               page,
				   gint               rotation,
				   gint              *width,
				   gint              *height)
{
	gint w, h;

	if (cache->uniform) {
		w = cache->uniform_width;
		h = cache->uniform_height;
	} else {
		EvThumbsSize *thumb_size;

		thumb_size = &(cache->sizes[page]);

		w = thumb_size->width;
		h = thumb_size->height;
	}

	if (rotation == 0 || rotation == 180) {
		if (width) *width = w;
		if (height) *height = h;
	} else {
		if (width) *width = h;
		if (height) *height = w;
	}
}

static void
ev_thumbnails_size_cache_free (EvThumbsSizeCache *cache)
{
	if (cache->sizes) {
		g_free (cache->sizes);
		cache->sizes = NULL;
	}

	g_free (cache);
}

static EvThumbsSizeCache *
ev_thumbnails_size_cache_get (EvDocument *document, gint width)
{
	EvThumbsSizeCache *cache;

	cache = g_object_get_data (G_OBJECT (document), EV_THUMBNAILS_SIZE_CACHE_KEY);
	if (!cache) {
		cache = ev_thumbnails_size_cache_new (document, width);
		g_object_set_data_full (G_OBJECT (document),
					EV_THUMBNAILS_SIZE_CACHE_KEY,
					cache,
					(GDestroyNotify)ev_thumbnails_size_cache_free);
	}

	return cache;
}


static void
ev_sidebar_thumbnails_dispose (GObject *object)
{
	EvSidebarThumbnails *sidebar_thumbnails = EV_SIDEBAR_THUMBNAILS (object);

	if (sidebar_thumbnails->priv->loading_icons) {
		g_hash_table_destroy (sidebar_thumbnails->priv->loading_icons);
		sidebar_thumbnails->priv->loading_icons = NULL;
	}

	if (sidebar_thumbnails->priv->list_store) {
		ev_sidebar_thumbnails_clear_model (sidebar_thumbnails);
		g_object_unref (sidebar_thumbnails->priv->list_store);
		sidebar_thumbnails->priv->list_store = NULL;
	}

	G_OBJECT_CLASS (ev_sidebar_thumbnails_parent_class)->dispose (object);
}

static void
ev_sidebar_thumbnails_get_property (GObject    *object,
				    guint       prop_id,
				    GValue     *value,
				    GParamSpec *pspec)
{
	EvSidebarThumbnails *sidebar = EV_SIDEBAR_THUMBNAILS (object);

	switch (prop_id) {
	case PROP_WIDGET:
		if (sidebar->priv->tree_view)
			g_value_set_object (value, sidebar->priv->tree_view);
		else
			g_value_set_object (value, sidebar->priv->icon_view);
		break;
	default:
		G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
		break;
	}
}

static void
ev_sidebar_thumbnails_map (GtkWidget *widget)
{
	EvSidebarThumbnails *sidebar;

	sidebar = EV_SIDEBAR_THUMBNAILS (widget);

	GTK_WIDGET_CLASS (ev_sidebar_thumbnails_parent_class)->map (widget);

	adjustment_changed_cb (sidebar);
}

gboolean
ev_sidebar_thumbnails_can_zoom_in  (EvSidebarThumbnails *sidebar_thumbnails)
{
    EvSidebarThumbnailsPrivate *priv = sidebar_thumbnails->priv;

    return priv->thumbnail_width < THUMBNAIL_MAX_WIDTH;
}

gboolean
ev_sidebar_thumbnails_can_zoom_out (EvSidebarThumbnails *sidebar_thumbnails)
{
    EvSidebarThumbnailsPrivate *priv = sidebar_thumbnails->priv;

    return priv->thumbnail_width > THUMBNAIL_MIN_WIDTH;
}

void
ev_sidebar_thumbnails_zoom_in (EvSidebarThumbnails *sidebar_thumbnails)
{
    EvSidebarThumbnailsPrivate *priv = sidebar_thumbnails->priv;

    ev_sidebar_thumbnails_set_size (sidebar_thumbnails,
                                    priv->thumbnail_width + THUMBNAIL_STEP_WIDTH);
    g_signal_emit (sidebar_thumbnails, signals[SIZE_CHANGED], 0, priv->thumbnail_width);
}

void
ev_sidebar_thumbnails_zoom_out (EvSidebarThumbnails *sidebar_thumbnails)
{
    EvSidebarThumbnailsPrivate *priv = sidebar_thumbnails->priv;

    ev_sidebar_thumbnails_set_size (sidebar_thumbnails,
                                    priv->thumbnail_width - THUMBNAIL_STEP_WIDTH);
    g_signal_emit (sidebar_thumbnails, signals[SIZE_CHANGED], 0, priv->thumbnail_width);
}

void
ev_sidebar_thumbnails_zoom_reset (EvSidebarThumbnails *sidebar_thumbnails)
{
    EvSidebarThumbnailsPrivate *priv = sidebar_thumbnails->priv;

    ev_sidebar_thumbnails_set_size (sidebar_thumbnails,
                                    THUMBNAIL_DEFAULT_WIDTH);
    g_signal_emit (sidebar_thumbnails, signals[SIZE_CHANGED], 0, priv->thumbnail_width);
}

void
ev_sidebar_thumbnails_cmd_zoom_in (GtkWidget *widget,
                                   EvSidebarThumbnails *sidebar_thumbnails)
{
    if (ev_sidebar_thumbnails_can_zoom_in (sidebar_thumbnails))
        ev_sidebar_thumbnails_zoom_in (sidebar_thumbnails);
}

void
ev_sidebar_thumbnails_cmd_zoom_out (GtkWidget *widget,
                                    EvSidebarThumbnails *sidebar_thumbnails)
{
    if (ev_sidebar_thumbnails_can_zoom_out (sidebar_thumbnails))
        ev_sidebar_thumbnails_zoom_out (sidebar_thumbnails);
}
void
ev_sidebar_thumbnails_cmd_zoom_reset (GtkWidget *widget,
                                   EvSidebarThumbnails *sidebar_thumbnails)
{
    if (sidebar_thumbnails->priv->thumbnail_width != THUMBNAIL_DEFAULT_WIDTH)
        ev_sidebar_thumbnails_zoom_reset (sidebar_thumbnails);
}

void
ev_sidebar_thumbnails_set_size (EvSidebarThumbnails *sidebar_thumbnails, gint size)
{
    EvSidebarThumbnailsPrivate *priv = sidebar_thumbnails->priv;
    priv->thumbnail_width = size;

    if (priv->thumbnail_width >= THUMBNAIL_MAX_WIDTH)
        priv->thumbnail_width = THUMBNAIL_MAX_WIDTH;
    else if (priv->thumbnail_width <= THUMBNAIL_MIN_WIDTH)
        priv->thumbnail_width = THUMBNAIL_MIN_WIDTH;

    if (priv->icon_view)
        gtk_icon_view_set_item_width (GTK_ICON_VIEW (priv->icon_view), priv->thumbnail_width);

    ev_sidebar_thumbnails_reload (sidebar_thumbnails);
}

static gboolean
ev_sidebar_thumbnails_scroll_event (GtkWidget           *widget,
                                    GdkEventScroll      *event,
                                    EvSidebarThumbnails *sidebar_thumbnails)
{
    guint state = event->state & gtk_accelerator_get_default_mod_mask ();

    if (state == GDK_CONTROL_MASK) {
        if ((event->delta_y < 0 || event->delta_x > 0)
          && ev_sidebar_thumbnails_can_zoom_in (sidebar_thumbnails)) {
            ev_sidebar_thumbnails_zoom_in (sidebar_thumbnails);
            return TRUE;
        } else if ((event->delta_y > 0 || event->delta_x < 0)
                 && ev_sidebar_thumbnails_can_zoom_out (sidebar_thumbnails)) {
            ev_sidebar_thumbnails_zoom_out (sidebar_thumbnails);
            return TRUE;
        }
    }

    return FALSE;
}

static void
ev_sidebar_thumbnails_class_init (EvSidebarThumbnailsClass *ev_sidebar_thumbnails_class)
{
	GObjectClass *g_object_class;
	GtkWidgetClass *widget_class;

	g_object_class = G_OBJECT_CLASS (ev_sidebar_thumbnails_class);
	widget_class = GTK_WIDGET_CLASS (ev_sidebar_thumbnails_class);

	g_object_class->dispose = ev_sidebar_thumbnails_dispose;
	g_object_class->get_property = ev_sidebar_thumbnails_get_property;

	widget_class->map = ev_sidebar_thumbnails_map;

#if GTK_CHECK_VERSION(3, 20, 0)
	gtk_widget_class_set_css_name (widget_class, "evsidebarthumbnails");
#endif

	g_object_class_override_property (g_object_class,
					  PROP_WIDGET,
					  "main-widget");


	signals[SIZE_CHANGED] =
		g_signal_new ("size-changed",
			      G_TYPE_FROM_CLASS (g_object_class),
			      G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION,
			      G_STRUCT_OFFSET (EvSidebarThumbnailsClass, size_changed),
			      NULL, NULL,
			      g_cclosure_marshal_VOID__POINTER,
			      G_TYPE_NONE, 1,
			      G_TYPE_POINTER);
}

GtkWidget *
ev_sidebar_thumbnails_new (void)
{
	GtkWidget *ev_sidebar_thumbnails;

	ev_sidebar_thumbnails = g_object_new (EV_TYPE_SIDEBAR_THUMBNAILS, NULL);

	return ev_sidebar_thumbnails;
}

static GdkPixbuf *
ev_sidebar_thumbnails_get_loading_icon (EvSidebarThumbnails *sidebar_thumbnails,
					gint                 width,
					gint                 height)
{
	EvSidebarThumbnailsPrivate *priv = sidebar_thumbnails->priv;
	GdkPixbuf *icon;
	gchar     *key;

	key = g_strdup_printf ("%dx%d", width, height);
	icon = g_hash_table_lookup (priv->loading_icons, key);
	if (!icon) {
		gboolean inverted_colors;

		inverted_colors = ev_document_model_get_inverted_colors (priv->model);
        icon = ev_document_misc_render_loading_thumbnail (GTK_WIDGET (sidebar_thumbnails),
                                                          width, height, inverted_colors);
		g_hash_table_insert (priv->loading_icons, key, icon);
	} else {
		g_free (key);
	}

	return icon;
}

static void
cancel_running_jobs (EvSidebarThumbnails *sidebar_thumbnails,
	     gint                 start_page,
	     gint                 end_page)
{
	EvSidebarThumbnailsPrivate *priv = sidebar_thumbnails->priv;
	GtkTreePath *path;
	GtkTreeIter iter;
	gboolean result;

	g_assert (start_page <= end_page);

	path = gtk_tree_path_new_from_indices (start_page, -1);
	for (result = gtk_tree_model_get_iter (GTK_TREE_MODEL (priv->list_store), &iter, path);
	     result && start_page <= end_page;
	     result = gtk_tree_model_iter_next (GTK_TREE_MODEL (priv->list_store), &iter), start_page ++) {

		EvJobThumbnail *job;

		/*
		 * We do not need to check COLUMN_THUMBNAIL_SET here, because it will always be
		 * TRUE, if the job is done (=NULL) and FALSE if the job is running.
		 */
		gtk_tree_model_get (GTK_TREE_MODEL (priv->list_store),
				    &iter,
				    COLUMN_JOB, &job,
				    -1);

		if (job) {
			g_signal_handlers_disconnect_by_func (job, thumbnail_job_completed_callback, sidebar_thumbnails);
			ev_job_cancel (EV_JOB (job));
			g_object_unref (job);
		}

		gtk_list_store_set (priv->list_store, &iter,
				    COLUMN_JOB, NULL,
				    COLUMN_THUMBNAIL_SET, FALSE,
				    -1);
	}
	gtk_tree_path_free (path);
}

static gdouble
get_scale_for_page (EvSidebarThumbnails *sidebar_thumbnails,
		    gint                 page)
{
	EvSidebarThumbnailsPrivate *priv = sidebar_thumbnails->priv;
	gdouble width;
	if (priv->document->iswebdocument == TRUE ) {
		/* Hardcoded for epub documents*/
		width = 800;
	} else {
		ev_document_get_page_size (priv->document, page, &width, NULL);
	}
	return (gdouble)priv->thumbnail_width / width;
}

static void
add_range (EvSidebarThumbnails *sidebar_thumbnails,
	   gint                 start_page,
	   gint                 end_page)
{
	EvSidebarThumbnailsPrivate *priv = sidebar_thumbnails->priv;
	GtkTreePath *path;
	GtkTreeIter iter;
	gboolean result;
	gint page = start_page;

	g_assert (start_page <= end_page);

	path = gtk_tree_path_new_from_indices (start_page, -1);
	for (result = gtk_tree_model_get_iter (GTK_TREE_MODEL (priv->list_store), &iter, path);
	     result && page <= end_page;
	     result = gtk_tree_model_iter_next (GTK_TREE_MODEL (priv->list_store), &iter), page ++) {
		EvJob *job;
		gboolean thumbnail_set;

		gtk_tree_model_get (GTK_TREE_MODEL (priv->list_store), &iter,
				    COLUMN_JOB, &job,
				    COLUMN_THUMBNAIL_SET, &thumbnail_set,
				    -1);

		if (job == NULL && !thumbnail_set) {
			job = ev_job_thumbnail_new (priv->document,
						    page, priv->rotation,
						    get_scale_for_page (sidebar_thumbnails, page));

			if (priv->document->iswebdocument) {
				ev_job_set_run_mode(job, EV_JOB_RUN_MAIN_LOOP);
			}

			g_object_set_data_full (G_OBJECT (job), "tree_iter",
						gtk_tree_iter_copy (&iter),
						(GDestroyNotify) gtk_tree_iter_free);
			g_signal_connect (job, "finished",
					  G_CALLBACK (thumbnail_job_completed_callback),
					  sidebar_thumbnails);
			gtk_list_store_set (priv->list_store, &iter,
					    COLUMN_JOB, job,
					    -1);

			ev_job_scheduler_push_job (EV_JOB (job), EV_JOB_PRIORITY_HIGH);

			/* The queue and the list own a ref to the job now */
			g_object_unref (job);
		} else if (job) {
			g_object_unref (job);
		}
	}
	gtk_tree_path_free (path);
}

/* This modifies start */
static void
update_visible_range (EvSidebarThumbnails *sidebar_thumbnails,
		      gint                 start_page,
		      gint                 end_page)
{
	EvSidebarThumbnailsPrivate *priv = sidebar_thumbnails->priv;
	int old_start_page, old_end_page;
	int n_pages_in_visible_range;

	/* Preload before and after current visible scrolling range, the same amount of
	 * thumbs in it, to help prevent thumbnail creation happening in the user's sight.
	 * https://bugzilla.gnome.org/show_bug.cgi?id=342110#c15 */
	n_pages_in_visible_range = (end_page - start_page) + 1;
	start_page = MAX (0, start_page - n_pages_in_visible_range);
	end_page = MIN (priv->n_pages - 1, end_page + n_pages_in_visible_range);

	old_start_page = priv->start_page;
	old_end_page = priv->end_page;

	if (start_page == old_start_page &&
	    end_page == old_end_page)
		return;

	/* Clear the areas we no longer display */
	if (old_start_page >= 0 && old_start_page < start_page)
		cancel_running_jobs (sidebar_thumbnails, old_start_page, MIN (start_page - 1, old_end_page));

	if (old_end_page > 0 && old_end_page > end_page)
		cancel_running_jobs (sidebar_thumbnails, MAX (end_page + 1, old_start_page), old_end_page);

	add_range (sidebar_thumbnails, start_page, end_page);

	priv->start_page = start_page;
	priv->end_page = end_page;
}

static void
adjustment_changed_cb (EvSidebarThumbnails *sidebar_thumbnails)
{
	EvSidebarThumbnailsPrivate *priv = sidebar_thumbnails->priv;
	GtkTreePath *path = NULL;
	GtkTreePath *path2 = NULL;
	gdouble page_size;
	gdouble value;
	gint wy1;
	gint wy2;

	/* Widget is not currently visible */
	if (!gtk_widget_get_mapped (GTK_WIDGET (sidebar_thumbnails)))
		return;

	page_size = gtk_adjustment_get_page_size (priv->vadjustment);

	if (page_size == 0)
		return;

	value = gtk_adjustment_get_value (priv->vadjustment);

	if (priv->tree_view) {
		if (! gtk_widget_get_realized (priv->tree_view))
			return;

		gtk_tree_view_convert_tree_to_bin_window_coords (GTK_TREE_VIEW (priv->tree_view),
								 0, (int) value,
								 NULL, &wy1);
		gtk_tree_view_convert_tree_to_bin_window_coords (GTK_TREE_VIEW (priv->tree_view),
								 0, (int) (value + page_size),
								 NULL, &wy2);
		gtk_tree_view_get_path_at_pos (GTK_TREE_VIEW (priv->tree_view),
					       1, wy1 + 1, &path,
					       NULL, NULL, NULL);
		gtk_tree_view_get_path_at_pos (GTK_TREE_VIEW (priv->tree_view),
					       1, wy2 -1, &path2,
					       NULL, NULL, NULL);
	} else if (priv->icon_view) {
		if (! gtk_widget_get_realized (priv->icon_view))
			return;
		if (! gtk_icon_view_get_visible_range (GTK_ICON_VIEW (priv->icon_view), &path, &path2))
			return;
	} else {
		return;
	}

	if (path && path2) {
		update_visible_range (sidebar_thumbnails,
				      gtk_tree_path_get_indices (path)[0],
				      gtk_tree_path_get_indices (path2)[0]);
	}

	gtk_tree_path_free (path);
	gtk_tree_path_free (path2);
}

static void
ev_sidebar_thumbnails_fill_model (EvSidebarThumbnails *sidebar_thumbnails)
{
	EvSidebarThumbnailsPrivate *priv = sidebar_thumbnails->priv;
	GtkTreeIter iter;
	int i;
	gint prev_width = -1;
	gint prev_height = -1;

    if (priv->document->iswebdocument) {
        return;
    }

	for (i = 0; i < sidebar_thumbnails->priv->n_pages; i++) {
		gchar     *page_label;
		gchar     *page_string;
		GdkPixbuf *loading_icon = NULL;
		gint       width, height;

		page_label = ev_document_get_page_label (priv->document, i);
		page_string = g_markup_printf_escaped ("<i>%s</i>", page_label);
		ev_thumbnails_size_cache_get_size (sidebar_thumbnails->priv->size_cache, i,
						  sidebar_thumbnails->priv->rotation,
						  &width, &height);

		height = (gint) ceil((double)(height) * priv->thumbnail_width / width);
		width = priv->thumbnail_width;

		if (!loading_icon || (width != prev_width && height != prev_height)) {
			loading_icon =
				ev_sidebar_thumbnails_get_loading_icon (sidebar_thumbnails,
									width, height);
		}

		prev_width = width;
		prev_height = height;

		gtk_list_store_append (priv->list_store, &iter);
		gtk_list_store_set (priv->list_store, &iter,
				    COLUMN_PAGE_STRING, page_string,
				    COLUMN_PIXBUF, loading_icon,
				    COLUMN_THUMBNAIL_SET, FALSE,
				    -1);
		g_free (page_label);
		g_free (page_string);
	}
}

static void
ev_sidebar_tree_selection_changed (GtkTreeSelection *selection,
				   EvSidebarThumbnails *ev_sidebar_thumbnails)
{
	EvSidebarThumbnailsPrivate *priv = ev_sidebar_thumbnails->priv;
	GtkTreePath *path;
	GtkTreeIter iter;
	int page;

	if (!gtk_tree_selection_get_selected (selection, NULL, &iter))
		return;

	path = gtk_tree_model_get_path (GTK_TREE_MODEL (priv->list_store),
					&iter);
	page = gtk_tree_path_get_indices (path)[0];
	gtk_tree_path_free (path);

	ev_document_model_set_page (priv->model, page);
}

static void
ev_sidebar_icon_selection_changed (GtkIconView         *icon_view,
				   EvSidebarThumbnails *ev_sidebar_thumbnails)
{
	EvSidebarThumbnailsPrivate *priv = ev_sidebar_thumbnails->priv;
	GtkTreePath *path;
	GList *selected;
	int page;

	selected = gtk_icon_view_get_selected_items (icon_view);
	if (selected == NULL)
		return;

	/* We don't handle or expect multiple selection. */
	g_assert (selected->next == NULL);

	path = selected->data;
	page = gtk_tree_path_get_indices (path)[0];

	gtk_tree_path_free (path);
	g_list_free (selected);

	ev_document_model_set_page (priv->model, page);
}

static void
ev_sidebar_init_tree_view (EvSidebarThumbnails *ev_sidebar_thumbnails)
{
	EvSidebarThumbnailsPrivate *priv;
	GtkTreeSelection *selection;
	GtkCellRenderer *renderer;

	gtk_orientable_set_orientation (GTK_ORIENTABLE (ev_sidebar_thumbnails), GTK_ORIENTATION_VERTICAL);

	priv = ev_sidebar_thumbnails->priv;
	priv->tree_view = gtk_tree_view_new_with_model (GTK_TREE_MODEL (priv->list_store));

	selection = gtk_tree_view_get_selection (GTK_TREE_VIEW (priv->tree_view));
	g_signal_connect (selection, "changed",
			  G_CALLBACK (ev_sidebar_tree_selection_changed), ev_sidebar_thumbnails);
	gtk_tree_view_set_headers_visible (GTK_TREE_VIEW (priv->tree_view), FALSE);
	renderer = g_object_new (GTK_TYPE_CELL_RENDERER_PIXBUF,
				 "xpad", 2,
				 "ypad", 2,
				 NULL);
	gtk_tree_view_insert_column_with_attributes (GTK_TREE_VIEW (priv->tree_view), -1,
						     NULL, renderer,
						     "pixbuf", 1,
						     NULL);
	gtk_tree_view_insert_column_with_attributes (GTK_TREE_VIEW (priv->tree_view), -1,
						     NULL, gtk_cell_renderer_text_new (),
						     "markup", 0, NULL);

	g_signal_connect (priv->tree_view, "scroll-event",
			  G_CALLBACK (ev_sidebar_thumbnails_scroll_event), ev_sidebar_thumbnails);

	gtk_container_add (GTK_CONTAINER (priv->swindow), priv->tree_view);
	gtk_widget_show (priv->tree_view);
}

static void
ev_sidebar_init_icon_view (EvSidebarThumbnails *ev_sidebar_thumbnails)
{
	EvSidebarThumbnailsPrivate *priv;
	GtkCellRenderer *renderer;

	priv = ev_sidebar_thumbnails->priv;

	priv->icon_view = gtk_icon_view_new_with_model (GTK_TREE_MODEL (priv->list_store));
	renderer = g_object_new (GTK_TYPE_CELL_RENDERER_PIXBUF,
				 "xalign", 0.5,
				 "yalign", 1.0,
				 NULL);
	gtk_cell_layout_pack_start (GTK_CELL_LAYOUT (priv->icon_view), renderer, FALSE);
	gtk_cell_layout_set_attributes (GTK_CELL_LAYOUT (priv->icon_view),
					renderer, "pixbuf", 1, NULL);

	renderer = g_object_new (GTK_TYPE_CELL_RENDERER_TEXT,
				 "alignment", PANGO_ALIGN_CENTER,
				 "wrap-mode", PANGO_WRAP_WORD_CHAR,
				 "xalign", 0.5,
				 "yalign", 0.0,
				 "width", THUMBNAIL_DEFAULT_WIDTH,
				 "wrap-width", THUMBNAIL_DEFAULT_WIDTH,
				 NULL);
	gtk_cell_layout_pack_end (GTK_CELL_LAYOUT (priv->icon_view), renderer, FALSE);
	gtk_cell_layout_set_attributes (GTK_CELL_LAYOUT (priv->icon_view),
					renderer, "markup", 0, NULL);
	g_signal_connect (priv->icon_view, "selection-changed",
			  G_CALLBACK (ev_sidebar_icon_selection_changed), ev_sidebar_thumbnails);

	g_signal_connect (priv->icon_view, "selection-changed",
			  G_CALLBACK (ev_sidebar_icon_selection_changed), ev_sidebar_thumbnails);

	g_signal_connect (priv->icon_view, "scroll-event",
			  G_CALLBACK (ev_sidebar_thumbnails_scroll_event), ev_sidebar_thumbnails);

	gtk_container_add (GTK_CONTAINER (priv->swindow), priv->icon_view);
	gtk_widget_show (priv->icon_view);
}

static gboolean
ev_sidebar_thumbnails_use_icon_view (EvSidebarThumbnails *sidebar_thumbnails)
{
	EvSidebarThumbnailsPrivate *priv = sidebar_thumbnails->priv;

	return (ev_document_get_n_pages (priv->document) <= MAX_ICON_VIEW_PAGE_COUNT);
}

static void
ev_sidebar_thumbnails_row_changed (GtkTreeModel *model,
                                   GtkTreePath  *path,
                                   GtkTreeIter  *iter,
                                   gpointer      data)
{
	guint signal_id;

	signal_id = GPOINTER_TO_UINT (data);

	/* PREVENT GtkIconView "row-changed" handler to be reached, as it will
	 * perform a full invalidate and relayout of all items, See bug:
	 * https://bugzilla.gnome.org/show_bug.cgi?id=691448#c9 */
	g_signal_stop_emission (model, signal_id, 0);
}

static void
ev_sidebar_thumbnails_init (EvSidebarThumbnails *ev_sidebar_thumbnails)
{
	EvSidebarThumbnailsPrivate *priv;
	GtkWidget *separator;
	guint signal_id;
	GtkWidget *toolbar;
	GtkWidget *toolitem;
	GtkWidget *button;
	GtkWidget *hbox;
	GtkWidget *image;

	priv = ev_sidebar_thumbnails->priv = ev_sidebar_thumbnails_get_instance_private (ev_sidebar_thumbnails);

	gtk_orientable_set_orientation (GTK_ORIENTABLE (ev_sidebar_thumbnails), GTK_ORIENTATION_VERTICAL);

	priv->list_store = gtk_list_store_new (NUM_COLUMNS,
					       G_TYPE_STRING,
					       GDK_TYPE_PIXBUF,
					       G_TYPE_BOOLEAN,
					       EV_TYPE_JOB_THUMBNAIL);

	signal_id = g_signal_lookup ("row-changed", GTK_TYPE_TREE_MODEL);
	g_signal_connect (GTK_TREE_MODEL (priv->list_store), "row-changed",
			  G_CALLBACK (ev_sidebar_thumbnails_row_changed),
			  GUINT_TO_POINTER (signal_id));

	priv->swindow = gtk_scrolled_window_new (NULL, NULL);

	priv->thumbnail_width = THUMBNAIL_DEFAULT_WIDTH;

	gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (priv->swindow),
					GTK_POLICY_NEVER, GTK_POLICY_AUTOMATIC);
	priv->vadjustment = gtk_scrolled_window_get_vadjustment (GTK_SCROLLED_WINDOW (priv->swindow));
	g_signal_connect_data (priv->vadjustment, "value-changed",
			       G_CALLBACK (adjustment_changed_cb),
			       ev_sidebar_thumbnails, NULL,
			       G_CONNECT_SWAPPED | G_CONNECT_AFTER);
	g_signal_connect_swapped (priv->swindow, "size-allocate",
				  G_CALLBACK (adjustment_changed_cb),
				  ev_sidebar_thumbnails);
	gtk_box_pack_start (GTK_BOX (ev_sidebar_thumbnails), priv->swindow, TRUE, TRUE, 0);

	separator = gtk_separator_new (GTK_ORIENTATION_HORIZONTAL);
	gtk_box_pack_start (GTK_BOX (ev_sidebar_thumbnails), separator, FALSE, FALSE, 0);
	gtk_widget_show (separator);

	toolbar = gtk_toolbar_new ();
	gtk_widget_show (toolbar);

	toolitem = GTK_WIDGET (gtk_tool_item_new ());
	gtk_toolbar_insert (GTK_TOOLBAR (toolbar), GTK_TOOL_ITEM (toolitem), 0);
	gtk_widget_show (toolitem);

	hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
	gtk_container_add (GTK_CONTAINER (toolitem), hbox);
	gtk_widget_show (hbox);

	button = gtk_button_new ();
	gtk_button_set_relief (GTK_BUTTON (button), GTK_RELIEF_NONE);
	image = gtk_image_new_from_icon_name ("xsi-zoom-out-symbolic", GTK_ICON_SIZE_BUTTON);
	gtk_container_add (GTK_CONTAINER (button), image);
	gtk_widget_show (image);

	gtk_box_pack_start (GTK_BOX (hbox), button, FALSE, FALSE, 0);
	gtk_widget_set_tooltip_text (GTK_WIDGET (button), _("Shrink the thumbnails"));
	g_signal_connect (button, "clicked",
			  G_CALLBACK (ev_sidebar_thumbnails_cmd_zoom_out),
			  ev_sidebar_thumbnails);
	gtk_widget_show (GTK_WIDGET (button));

	button = gtk_button_new ();
	gtk_button_set_relief (GTK_BUTTON (button), GTK_RELIEF_NONE);
	image = gtk_image_new_from_icon_name ("xsi-zoom-in-symbolic", GTK_ICON_SIZE_BUTTON);
	gtk_container_add (GTK_CONTAINER (button), image);
	gtk_widget_show (image);

	gtk_box_pack_start (GTK_BOX (hbox), button, FALSE, FALSE, 0);
	gtk_widget_set_tooltip_text (GTK_WIDGET (button), _("Enlarge the thumbnails"));
	g_signal_connect (button, "clicked",
			  G_CALLBACK (ev_sidebar_thumbnails_cmd_zoom_in),
			  ev_sidebar_thumbnails);
	gtk_widget_show (GTK_WIDGET (button));

	button = gtk_button_new ();
	gtk_button_set_relief (GTK_BUTTON (button), GTK_RELIEF_NONE);
	image = gtk_image_new_from_icon_name ("xsi-zoom-original-symbolic", GTK_ICON_SIZE_BUTTON);
	gtk_container_add (GTK_CONTAINER (button), image);
	gtk_widget_show (image);

	gtk_box_pack_start (GTK_BOX (hbox), button, FALSE, FALSE, 0);
	gtk_widget_set_tooltip_text (GTK_WIDGET (button), _("View the thumbnails at their original size"));
	g_signal_connect (button, "clicked",
			  G_CALLBACK (ev_sidebar_thumbnails_cmd_zoom_reset),
			  ev_sidebar_thumbnails);
	gtk_widget_show (GTK_WIDGET (button));

	/* Put it all together */
	gtk_box_pack_end (GTK_BOX (ev_sidebar_thumbnails), toolbar, FALSE, TRUE, 0);
	gtk_widget_show_all (priv->swindow);
}

static void
ev_sidebar_thumbnails_set_current_page (EvSidebarThumbnails *sidebar,
					gint                 page)
{
	GtkTreeView *tree_view;
	GtkTreePath *path;

	path = gtk_tree_path_new_from_indices (page, -1);

	if (sidebar->priv->tree_view) {
		tree_view = GTK_TREE_VIEW (sidebar->priv->tree_view);
		gtk_tree_view_set_cursor (tree_view, path, NULL, FALSE);
		gtk_tree_view_scroll_to_cell (tree_view, path, NULL, FALSE, 0.0, 0.0);
	} else if (sidebar->priv->icon_view) {

		g_signal_handlers_block_by_func
			(sidebar->priv->icon_view,
			 G_CALLBACK (ev_sidebar_icon_selection_changed), sidebar);

		gtk_icon_view_select_path (GTK_ICON_VIEW (sidebar->priv->icon_view), path);

		g_signal_handlers_unblock_by_func
			(sidebar->priv->icon_view,
			 G_CALLBACK (ev_sidebar_icon_selection_changed), sidebar);

		gtk_icon_view_scroll_to_path (GTK_ICON_VIEW (sidebar->priv->icon_view), path, FALSE, 0.0, 0.0);
	}

	gtk_tree_path_free (path);
}

static void
page_changed_cb (EvSidebarThumbnails *sidebar,
		 gint                 old_page,
		 gint                 new_page)
{
	ev_sidebar_thumbnails_set_current_page (sidebar, new_page);
}

static gboolean
refresh (EvSidebarThumbnails *sidebar_thumbnails)
{
	adjustment_changed_cb (sidebar_thumbnails);
	return FALSE;
}

static void
ev_sidebar_thumbnails_reload (EvSidebarThumbnails *sidebar_thumbnails)
{
	EvDocumentModel *model;

	if (sidebar_thumbnails->priv->loading_icons)
		g_hash_table_remove_all (sidebar_thumbnails->priv->loading_icons);

	if (sidebar_thumbnails->priv->document == NULL ||
	    sidebar_thumbnails->priv->n_pages <= 0)
		return;

	model = sidebar_thumbnails->priv->model;

	ev_sidebar_thumbnails_clear_model (sidebar_thumbnails);
	ev_sidebar_thumbnails_fill_model (sidebar_thumbnails);

	/* Trigger a redraw */
	sidebar_thumbnails->priv->start_page = -1;
	sidebar_thumbnails->priv->end_page = -1;
	ev_sidebar_thumbnails_set_current_page (sidebar_thumbnails,
						ev_document_model_get_page (model));

	g_idle_add ((GSourceFunc)refresh, sidebar_thumbnails);
}

static void
ev_sidebar_thumbnails_rotation_changed_cb (EvDocumentModel     *model,
					   GParamSpec          *pspec,
					   EvSidebarThumbnails *sidebar_thumbnails)
{
	gint rotation = ev_document_model_get_rotation (model);

	sidebar_thumbnails->priv->rotation = rotation;
	ev_sidebar_thumbnails_reload (sidebar_thumbnails);
}

static void
ev_sidebar_thumbnails_inverted_colors_changed_cb (EvDocumentModel     *model,
						  GParamSpec          *pspec,
						  EvSidebarThumbnails *sidebar_thumbnails)
{
	gboolean inverted_colors = ev_document_model_get_inverted_colors (model);

	sidebar_thumbnails->priv->inverted_colors = inverted_colors;
	ev_sidebar_thumbnails_reload (sidebar_thumbnails);
}

static void
thumbnail_job_completed_callback (EvJobThumbnail      *job,
				  EvSidebarThumbnails *sidebar_thumbnails)
{
	EvSidebarThumbnailsPrivate *priv = sidebar_thumbnails->priv;
	GtkTreeIter   *iter;
    GdkPixbuf     *pixbuf;

    pixbuf = ev_document_misc_render_thumbnail_with_frame (GTK_WIDGET (sidebar_thumbnails), job->thumbnail);

	iter = (GtkTreeIter *) g_object_get_data (G_OBJECT (job), "tree_iter");
	if (priv->inverted_colors && priv->document->iswebdocument == FALSE)
		ev_document_misc_invert_pixbuf (pixbuf);
	gtk_list_store_set (priv->list_store,
			    iter,
			    COLUMN_PIXBUF, pixbuf,
			    COLUMN_THUMBNAIL_SET, TRUE,
			    COLUMN_JOB, NULL,
			    -1);

	gtk_widget_queue_draw (priv->icon_view);
    g_object_unref (pixbuf);
}

static void
ev_sidebar_thumbnails_document_changed_cb (EvDocumentModel     *model,
					   GParamSpec          *pspec,
					   EvSidebarThumbnails *sidebar_thumbnails)
{
	EvDocument *document = ev_document_model_get_document (model);
	EvSidebarThumbnailsPrivate *priv = sidebar_thumbnails->priv;

	if (!EV_IS_DOCUMENT_THUMBNAILS (document) ||
	    ev_document_get_n_pages (document) <= 0 ||
	    !ev_document_check_dimensions (document)) {
		return;
	}

	priv->size_cache = ev_thumbnails_size_cache_get (document, priv->thumbnail_width);
	priv->document = document;
	priv->n_pages = ev_document_get_n_pages (document);
	priv->rotation = ev_document_model_get_rotation (model);
	priv->inverted_colors = ev_document_model_get_inverted_colors (model);
	priv->loading_icons = g_hash_table_new_full (g_str_hash,
						     g_str_equal,
						     (GDestroyNotify)g_free,
						     (GDestroyNotify)g_object_unref);

	ev_sidebar_thumbnails_clear_model (sidebar_thumbnails);
	ev_sidebar_thumbnails_fill_model (sidebar_thumbnails);

	/* Create the view widget, and remove the old one, if needed */
	if (ev_sidebar_thumbnails_use_icon_view (sidebar_thumbnails)) {
		if (priv->tree_view) {
			gtk_container_remove (GTK_CONTAINER (priv->swindow), priv->tree_view);
			priv->tree_view = NULL;
		}

		if (! priv->icon_view) {
			ev_sidebar_init_icon_view (sidebar_thumbnails);
			g_object_notify (G_OBJECT (sidebar_thumbnails), "main_widget");
		} else {
			gtk_widget_queue_resize (priv->icon_view);
		}
	} else {
		if (priv->icon_view) {
			gtk_container_remove (GTK_CONTAINER (priv->swindow), priv->icon_view);
			priv->icon_view = NULL;
		}

		if (! priv->tree_view) {
			ev_sidebar_init_tree_view (sidebar_thumbnails);
			g_object_notify (G_OBJECT (sidebar_thumbnails), "main_widget");
		}
	}

	/* Connect to the signal and trigger a fake callback */
	g_signal_connect_swapped (priv->model, "page-changed",
				  G_CALLBACK (page_changed_cb),
				  sidebar_thumbnails);
	g_signal_connect (priv->model, "notify::rotation",
			  G_CALLBACK (ev_sidebar_thumbnails_rotation_changed_cb),
			  sidebar_thumbnails);
	g_signal_connect (priv->model, "notify::inverted-colors",
			  G_CALLBACK (ev_sidebar_thumbnails_inverted_colors_changed_cb),
			  sidebar_thumbnails);
	sidebar_thumbnails->priv->start_page = -1;
	sidebar_thumbnails->priv->end_page = -1;
	ev_sidebar_thumbnails_set_current_page (sidebar_thumbnails,
						ev_document_model_get_page (model));
	adjustment_changed_cb (sidebar_thumbnails);
}

static void
ev_sidebar_thumbnails_set_model (EvSidebarPage   *sidebar_page,
				 EvDocumentModel *model)
{
	EvSidebarThumbnails *sidebar_thumbnails = EV_SIDEBAR_THUMBNAILS (sidebar_page);
	EvSidebarThumbnailsPrivate *priv = sidebar_thumbnails->priv;

	if (priv->model == model)
		return;

	priv->model = model;
	g_signal_connect (model, "notify::document",
			  G_CALLBACK (ev_sidebar_thumbnails_document_changed_cb),
			  sidebar_page);
}

static gboolean
ev_sidebar_thumbnails_clear_job (GtkTreeModel *model,
			         GtkTreePath *path,
			         GtkTreeIter *iter,
				 gpointer data)
{
	EvJob *job;

	gtk_tree_model_get (model, iter, COLUMN_JOB, &job, -1);

	if (job != NULL) {
		ev_job_cancel (job);
		g_signal_handlers_disconnect_by_func (job, thumbnail_job_completed_callback, data);
		g_object_unref (job);
	}

	return FALSE;
}

static void
ev_sidebar_thumbnails_clear_model (EvSidebarThumbnails *sidebar_thumbnails)
{
	EvSidebarThumbnailsPrivate *priv = sidebar_thumbnails->priv;

	gtk_tree_model_foreach (GTK_TREE_MODEL (priv->list_store), ev_sidebar_thumbnails_clear_job, sidebar_thumbnails);
	gtk_list_store_clear (priv->list_store);
}

static gboolean
ev_sidebar_thumbnails_support_document (EvSidebarPage   *sidebar_page,
				        EvDocument *document)
{
    return (EV_IS_DOCUMENT_THUMBNAILS (document) && !document->iswebdocument);
}

static const gchar*
ev_sidebar_thumbnails_get_label (EvSidebarPage *sidebar_page)
{
	return _("Thumbnails");
}

static void
ev_sidebar_thumbnails_page_iface_init (EvSidebarPageInterface *iface)
{
	iface->support_document = ev_sidebar_thumbnails_support_document;
	iface->set_model = ev_sidebar_thumbnails_set_model;
	iface->get_label = ev_sidebar_thumbnails_get_label;
}
